This invention relates to a versatile, low cost form of construction for a direct-reading fluent density sensor that may;
with the addition of a modular torque reaction detector, be used as a direct-reading fluent density and mass flow sensor, operating on gyroscopic reaction principles, or; PA1 with the addition of a modular volumetric flow sensor, be used as a direct-reading fluent mass density and inferential mass flow sensor, or; PA1 with the incorporation of an integral flow velocity sensor be used as a direct reading mass density and inferential mass flow sensor. PA1 (All sensors referred to herein are used to measure the mass density and/or mass flow rate of fluids. Hereinafter, the terms density or mass density are intended to identically mean fluid mass density, and the terms flow or mass flow are intended to identically mean fluid mass flow rate.) PA1 a) in the gyroscopic form, an internal conduit rotates or oscillates as a whole relative to the frame of the meter; in the coriolis form, the internal conduit (or conduits) flexes or bends relative to the frame of the meter, PA1 b) in the gyroscopic form, the gyroscopic couple due to the inertial reaction of the fluent flowing in the internal conduit is measured directly; in the coriolis form, the coriolis forces due to the inertial reaction of the fluent flowing in the internal conduit act to modulate the motion response of the flexing internal conduit and this change in motion response is used as the measure of the inertial reaction, PA1 (In the review of the prior art, the search found only one example of a mass density sensor operation on a direct inertial reaction principle, the Dynatrol.RTM. Cell CL-10TY series, a product of Automation Products Inc., Texas, Patents Pending. This device shares many costly design features in common with the coriolis mass flow sensors discussed in paragraphs E, F and I of this section. Therefore, the discussion in these paragraphs of previous art in regard to coriolis mass flow sensors also covers mass density sensors of the Dynatrol.RTM. type.)